/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package zipkin2.server.internal;

import org.springframework.boot.actuate.health.CompositeHealthIndicator;
import org.springframework.boot.actuate.health.Health;
import org.springframework.boot.actuate.health.HealthAggregator;
import org.springframework.boot.actuate.health.HealthIndicator;
import zipkin2.CheckResult;
import zipkin2.Component;

final class ZipkinHealthIndicator extends CompositeHealthIndicator {

  ZipkinHealthIndicator(HealthAggregator healthAggregator) {
    super(healthAggregator);
  }

  void addComponent(Component component) {
    String healthName = component.getClass().getSimpleName();
    healthName = healthName.replace("AutoValue_", "");
    addHealthIndicator(healthName, new ComponentHealthIndicator(component));
  }

  static final class ComponentHealthIndicator implements HealthIndicator {
    final Component component;

    ComponentHealthIndicator(Component component) {
      this.component = component;
    }

    /** synchronized to prevent overlapping requests to a storage backend */
    @Override
    public synchronized Health health() {
      CheckResult result = component.check();
      return result.ok() ? Health.up().build() : Health.down((Exception) result.error()).build();
    }
  }
}
